3. Another mode of discrimination inhering in our muscular consciousness is the degree of movement, as slow or quick. We are differently affected according to the rapidity of our movements; an accelerated pace in the arm, or in the whole body, sensibly alters our feelings. Farther, we do not compound this alteration with its dynamical equivalents in the 149 other modes—with increase in the amount of the dead strain, in the continuance of the dead strain, or in the continuance of movement. A characteristic mode of feeling attends this special form of augmenting or reducing our expenditure of force. The consequence is, a feeling of velocity or speed of movement. But this feeling of speed is not all. We gain another equivalent of degrees of extension; more speed in the same time being equal to more time with the same speed. It is proper to remark, however, that we are premature in speaking of extension, or in regarding it as arrived at, at once by our primary experiences of movement; much has to be gone through before this is fully formed or developed. Motion is the fundamental fact, but motion is a fact of succession, and can do nothing to suggest a group of contemporaneous phenomena, an outspread universe of the co-existing in time. Our primary sensibility is a mere thread of succession, duration, or continuance; we have to acquire by a process of aggregation and association, the highly artificial experience of things permanently situated in a relationship of co-existence in space or extension.
It is at this point that Sensation comes to our aid. Passive sensation by itself is incompetent to give us the foundations of extension; through it, we have neither resistance nor movement, nor any fact partaking in what is essential to the extended or object universe. Mere warmth, odour, relish, touch, sound, colour, contain no elements of extension. The co-operation with moving energy is what introduces us to the object world.
How then does Sensation aid muscularity in evolving Extension? In various ways, but chiefly thus. Our movements are not performed in vacuo, but in conjunction with sensation. The movements of the hand and arm, are usually conjoined with sensations of touch. We draw the hand across a table; there is an arm sensibility, purely motor or energetic, which is distinct from every mode of passive sensation. There accompanies it, however, a series of tactile sensations, making a united experience, active and passive. If this conjunction 150 were to happen but once, nothing would be thought of it farther than as a mere experience of succession. Again, in another situation the sweep of the movement ends in a contact or sensation of touch, or begins in the loss of such a contact. So far, these are mere casual conjunctions, unions of moving energy and passive sensibility. But in the course of many trials, there arise uniform conjunctions of movement with passive sensibility: the same movement being associated with the same tactile series, or with the same beginning or ending of tactile sensation. Take the case of the movement of the hand over the surface of our own body. A certain definite start, and definite amount of exertion brings with it a uniform tactile sensation, as in drawing the hand over the face. This uniformity generates an expectation that the same sensation will follow on the same definite energy. Many such conjunctions are formed in this manner. There is an interesting variety of the experience of such concurrences; namely, when we reverse a movement, and find a series of sensations identified as the same in an inverted order. The hand passed along the side of a knife, experiences movement coupled with sensations, as often as the movement is made; the inverted movement inverts the sensations.
The supposition, hitherto, has been confined to Touch. When we take in sight, the scope for the operation is greatly enlarged. Almost all our movements are conjoined with optical changes—sensations of colour and of visible form in a certain sequence. We speedily detect a number of uniform occurrences of movement and visible sensation. The same movement gives the same series of appearances at all times; and an inverted movement corresponds with an inverted order. Here too we attain to a number of uniformities of coincidence, with the expectation of future occurrence. A certain movement of the eyes is accompanied with an optical series, as scanning the starry heavens; as often as the movement is repeated from the same stand-point, the optical series is repeated; the inverted movement gives the inverted series. We 151 contract an expectation, that such a coincidence will occur in the future, and this expectation is our idea of the starry space.
Our idea of extended things is thus completed by sensation. It is a series of conjunctions, or associations, of movements and sensations, in a fixed order. We do not in our idea of space, command an entire view at one glance; the successive perception of points or limited portions is what we begin with, and is the character of the mind’s working even after we are educated to the utmost. The co-existing in space, is the mind’s potentiality of finding definite sensations by means of definite movements; and it seems impossible to assign any other meaning or import to the phenomena. The genesis of the idea of space determines our mode of settling the great question of the Perception of a material world.—B.
[32] It will be both useful and interesting to the inquiring reader, if I add to the analysis of these very complex ideas by the author of the present treatise, and to that by Mr. Bain, the analysis given of them by the other great living master of the Association psychology, Mr. Herbert Spencer. The following passages are from his “Principles of Psychology.” First, of Resistance:
“On raising the arm to a horizontal position and keeping it so, and still more on dealing similarly with the leg, a sensation is felt, which, tolerably strong as it is at the outset, presently becomes unbearable. If the limb be uncovered, and be not brought against anything, this sensation is associated with no other, either of touch or pressure.” This is the sensation of Muscular Tension.
“Allied to the sensation accompanying tension of the muscles, is that accompanying the act of contracting them—the sensation of muscular motion.… While, from the muscles of a limb at rest, no sensation rises; while, from the muscles of a limb in a state of continuous strain, there arises a continuous sensation which remains uniform for a considerable time; from the muscle of a limb in motion, there arises a sensation which is 152 ever undergoing increase or decrease, or change of composition.
“When we express our immediate experiences of a body by saying that it is hard, what are the experiences implied? First, a sensation of pressure, of considerable intensity, is implied; and if, as in most cases, this sensation of pressure is given to a finger voluntarily thrust against the object, then there is simultaneously felt a correspondingly strong sensation of muscular tension. But this is not all: for feelings of pressure and muscular tension may be given by bodies which we call soft, provided the compressing finger follows the surface as fast as it gives way. In what then consists the difference between the perceptions? In this; that whereas when a soft body is pressed with increasing force, the synchronous sensations of increasing pressure and increasing muscular tension are accompanied by sensations of muscular movement; when a hard body is pressed with increasing force these sensations of increasing pressure and tension are not accompanied by sensations of muscular movement. Considered by itself, then, the perception of softness may be defined as the establishment in consciousness of a relation of simultaneity between three series of sensations—a series of increasing sensations of pressure; a series of increasing sensations of tension; and a series of sensations of motion. And the perception of hardness is the same, with omission of the last series.” (pp. 212, 218.)
Of Extension; and first, of Form or Figure: